Test your microphone input instantly with our free Microphone Tester. Stream real-time Web Audio FFT frequency data to render live canvas waveforms and measure decibel peak volume levels with 100% browser-local privacy.
Click Request Microphone Access and authorize the browser permission prompt.
Speak into your mic and observe real-time frequency bars on the canvas.
Monitor live volume decibels and click Stop Mic Test when complete.
Uses 256-point Fast Fourier Transform (FFT) analysis to extract real-time byte frequency data from live MediaStream audio nodes.
Calculates peak frequency amplitudes normalized to a 0–100 relative decibel scale with 60fps canvas updates.
Audio streams remain strictly inside browser memory. Closing the mic stops all tracks immediately with zero telemetry sent to servers.
The HTML5 MediaDevices API allows web applications to request audio input streams via navigator.mediaDevices.getUserMedia({ audio: true }). Browsers prompt explicit user permission before granting access to input hardware.
Audio streams are connected to a Web Audio AudioContext and routed into an AnalyserNode with an FFT size of 256. getByteFrequencyData() retrieves frequency bins in real time, driving 60fps canvas visualizer animations.
Privacy is guaranteed because the audio stream is connected directly to local Web Audio processing nodes without any MediaRecorder or network transmission layers. Stopping the test calls track.stop(), releasing the microphone hardware immediately.